METHOD FOR ACCELERATING AND FLUIDIFYING WET CONCRETES OR MORTARS COMPOSITIONS COMPRISING AN ACTIVATING AGENT, A WATER REDUCING POLYMER, CONSISTING IN USING PERFORMANCE ADDITIVE INCLUDING CHAOTROPIC IONS AND ITS USE IN LOW CARBON ALTERNATIVE BINDER COMPOSITIONS

Abstract

The invention concerns a method for fluidifying wet concrete or industrial mortar compositions comprising: (a) at least one hydraulic binder, (b) at least one water reducing polymer, (c) at least one accelerator in the form of a salt containing at least one kosmotropic ion, (d) water, and (e) possibly one or more supplementary cementitious materials, and (f) possibly one or more filler materials, the method comprising a step of adding at least one salt (ch) including at least one chaotropic ion to the concrete or industrial mortar composition.

Claims

1. A method for fluidifying wet concrete or industrial mortar compositions comprising: (a) at least one hydraulic binder, (b) at least one water reducing polymer, (c) at least one accelerator in the form of a salt containing at least one kosmotropic ion, (d) water, and (e) possibly one or more supplementary cementitious materials, and (f) possibly one or more filler materials, the method comprising a step of adding of at least one salt (ch) including at least one chaotropic ion to the concrete or industrial mortar composition.

2. The method according to claim 1, wherein the dry weight ratio of salt (ch) comprising at least one chaotropic ion to said accelerator (c) is comprised between 0.01 and 3.0.

3. The method according to claim 1, wherein the water reducing polymer (b) is selected from the group consisting of lignosulfonate polymers, melamine sulfonate polymers, naphthalene sulfonate polymers, polycarboxylic acid ether polymers, polyoxyethylene phosphonates, vinyl copolymers, and mixtures thereof.

4. The method according to claim 1, wherein the kosmotropic ion of the accelerator (c) is an anion from the group consisting of carbonate (CO.sup.2-), sulfate (SO.sub.4.sup.2-), hydroxide (OH.sup.-), citrate (C.sub.6H.sub.5O.sub.7.sup.3-), phosphate (PO.sub.4.sup.3-), hydrogen phosphate (HPO.sub.4.sup.2-), dihydrogen phosphate (HPO.sub.4.sup.-), tartrate (C.sub.4H.sub.4O.sub.6.sup.2-), acetate (CH.sub.3COO.sup.-), formate (HCOO.sup.-), bicarbonate (HCO.sub.3.sup.-), orthosilicate (SiO.sub.4.sup.4-), metasilicate (SiO.sub.3.sup.2-), pyrosilicate (Si.sub.2O.sub.7.sup.6-), polyphosphates, polysilicates, and thiosulfate (S.sub.2O.sub.2.sup.3-).

5. The method according to claim 1, wherein the cation of the accelerator (c) is selected from the group consisting in sodium, potassium and lithium.

6. The method according to claim 1, wherein said chaotropic ion of the salt (ch) is selected from the group consisting of chloride (Cl.sup.-), bromide (Br.sup.-), nitrate (NO.sub.3.sup.-), chlorate (ClO.sub.3.sup.-), perchlorate (ClO.sub.4.sup.-), tetrafluoroborate (BF.sub.4.sup.-), iodide (I.sup.-), thiocyanate (SCN.sup.-), hexafluorophosphate (PF.sub.6.sup.-), guanidinium (C(NH.sub.2).sub.3.sup.+), trichloroacetate (CCl.sub.3COO.sup.- ), dichloroacetate (CHCl.sub.2COO.sup.-), chloroacetate (CH.sub.2ClCOO.sup.-), tribromoacetate (CBr.sub.3COO-), or trifluoroacetate (CF.sub.3COO.sup.-).

7. The method according to claim 1, wherein said salt (ch) including at least one chaotropic ion is selected from the group consisting of potassium thiocyanate (KSCN), potassium nitrate (KNO.sub.3), potassium chloride (KCI), sodium thiocyanate (NaSCN), sodium nitrate (NaNO.sub.3), sodium chloride (NaCl), magnesium chloride (MgCl.sub.2), magnesium nitrate (Mg(NO.sub.3).sub.2), calcium chloride (CaCl.sub.2), calcium nitrate (Ca(NO.sub.3).sub.2) calcium thiocyanate (Ca.sub.2SCN), barium chloride (BaCl.sub.2), strontium nitrate (Sr(NO.sub.3).sub.2), guanidinium chloride (CH.sub.6ClN.sub.3) and guanidinium thiocyanate (C.sub.2H.sub.6N.sub.4S).

8. The method according to claim 1, wherein the hydraulic binder (a) is selected from the group consisting of ordinary Portland cement, calcium aluminate cement, calcium sulfoaluminate cement, belite cement, hydraulic lime, ground granulated blast furnace slag, basic oxygen furnace slag, ladle slag, super sulfated cement, cement kiln dust, or a mixtures thereof.

9. The method according to claim 1, wherein the supplementary cementitious material (e) is selected from the group consisting of fly ash, activated clay, silica fume, basic oxygen furnace slag, natural pozzolanic materials, rice husk ash, activated recycled concrete fine aggregates or a mixtures thereof and/or wherein the filler material (f) is selected from the group consisting of ground limestone, ground dolomite, marble powder, siliceous sands, recycled concrete fine aggregates or a mixture thereof.

10. A use, as co-fluidifier with at least one water reducing polymer (b), of at least one salt (ch) including at least one chaotropic ion, of wet concrete or industrial mortar compositions comprising water, at least a binder fraction and at least one aggregate fraction, the binder fraction comprising: (a) at least one hydraulic binder, (b) at least one accelerator in the form of a salt containing at least one kosmotropic ion, (e) possibly one or more supplementary cementitious material, and (f) possibly one or more filler material.

11. The use according to claim 10, wherein said binder fraction comprises, in % by dry weight in respect with the total weight of hydraulic binder (a) supplementary cementitious material (e) and filler material (f): between 0.001 and 10, preferably between 0.01 and 5, and, more preferably, between 0.1 and 3, of said salt (ch) including at least one chaotropic ion, between 0.005 and 5.0 preferably between 0.01 and 3.0, and, more preferably, between 0.1 and 2, of said water reducing polymer (b), and between 0.1 and 10 preferably between 0.5 and 5, and, more preferably, between 1 and 3 of said accelerator (c).

12. A process for preparing wet concrete or mortar composition comprising a step of mixing together, simultaneously or not, separately or not, (a) at least one hydraulic binder, (b) at least one water reducing polymer, (c) at least one accelerator in the form of a salt containing at least one kosmotropic ion, (d) water, and (e) possibly one or more supplementary cementitious materials, and (f) possibly one or more filler materials, at least one salt (ch) including at least one chaotropic ion, and at least one aggregate fraction.

13. A ready mix concrete or precast concrete composition, devoted in particular to building construction and civil engineering works, comprising at least one aggregate fraction, at least one salt (ch) including at least one chaotropic ion, and (a) at least one hydraulic binder, (b) at least one water reducing polymer, (c) at least one accelerator in the form of a salt containing at least one kosmotropic ion, (d) water, and (e) possibly one or more supplementary cementitious materials, and (f) possibly one or more filler materials.

14. A method for fluidifying a wet concrete or industrial mortar composition comprising: (a) at least one hydraulic binder, (c) at least one accelerator in the form of a salt containing at least one kosmotropic ion, (d) water, and (e) possibly one or more supplementary cementitious materials, and (f) possibly one or more filler materials, the method comprising a step of addition, to the concrete or industrial mortar composition, of at least one salt (ch) including at least one chaotropic ion and at least one water reducing polymer (b) in a quantity, for obtaining said wet concrete or industrial mortar composition in a targeted consistency class according to European standard EN 206, not increased compared to a wet concrete or industrial mortar composition (CEC) comprising component a, c, d, possibly e, and possibly f, but not comprising component c of the same targeted consistency class.

15. A performance additive, having a free water content of less than 0.5% in weight, for accelerating and fluidifying wet concrete or industrial mortar compositions comprising at least one hydraulic binder (a), at least one water reducing polymer (b) at least one accelerator (c) in the form of a salt containing at least one kosmotropic ion; said additive including at least one salt (ch) including at least one chaotropic ion.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0056] FIGS. 1 to 7 are graphs of yield stress versus time after mixing of wet binder composition samples. These graphs present the impact of water reducing polymers (b), kosmotropic activating agents (c), and the salt (ch) including at least one chaotropic ion on the yield stress of paste samples.

[0057] FIGS. 8 to 10 are graphs of heat versus time after mixing of wet binder composition samples. These graphs present the impact of the invention on the heat produced by paste samples over the first 24 hours. Heat can be used as a proxy for evaluating the relative early-age strength of such binders due to the exothermic nature of the hydration of cementitious systems.

DETAILED DESCRIPTION OF THE INVENTION

The Method for Fluidifying Wet Concrete or Industrial Mortar Composition

[0058] The method for fluidifying wet concrete or industrial mortar composition comprises: the method comprising a step of addition of at least one salt (ch) including at least one chaotropic ion to the concrete or industrial mortar composition. [0059] (a) one hydraulic binder, [0060] (b) at least one water reducing polymer, [0061] (c) at least one accelerator in the form of a salt containing at least one kosmotropic ion, [0062] (d) water, and [0063] (e) possibly one or more supplementary cementitious materials, and [0064] (f) possibly one or more filler materials,

[0065] As used herein, a “kosmotropic ion” is an ion that enhances water structure and decreases the solubility of nonpolar solvent molecules or particles.

[0066] More specifically, in the meaning of the invention, an ion is considered as being kosmotropic if it decreases aqueous solubility of a given water reducing polymer. Indeed, the influence of an ion depends on the water reducing polymer used.

[0067] As used herein, a “chaotropic ion” is an ion that disrupts water structure, and increases the solubility of nonpolar solvent molecules or particles.

[0068] More specifically, in the meaning of the invention, an ion is considered as being chaotropic if it allows solubilizing a given water reducing polymer. Indeed, the influence of an ion depends on the water reducing polymer used.

The Use as a Co-Fluidifier of at Least One Salt (ch) Including at Least One Chaotropic Ion

[0069] As mentioned above, one objective of the invention is to provide concretes and industrial mortars with appropriate rheology in the wet state, before setting, and with good mechanical properties after setting, especially good early age strength. So as to achieve this objective, the invention also concerns the use, as a co-fluidifier with at least one water reducing polymer (b), of at least one salt (ch) including at least one chaotropic ion for wet concrete or industrial mortar compositions comprising water, at least a binder fraction and at least one aggregate fraction, the binder fraction comprising: [0070] (a) at least one hydraulic binder, [0071] (c) at least one accelerator in the form of a salt containing at least one kosmotropic ion, [0072] (e) possibly one or more supplementary cementitious material, and [0073] (f) possibly one or more filler material.

[0074] The amount of the salt (ch) including at least one chaotropic ion, as a co-fluidifier, in the binder fraction depends on the nature and quantities of the other components of the binder fraction. Therefore, the content of each component of the binder faction is determined in relation with the other binder fraction.

[0075] In a preferred embodiment, the binder fraction comprises, in % by dry weight in respect with the total weight of hydraulic binder (a) supplementary cementitious material (e) and filler material (f): [0076] between 0.001 and 10, preferably between 0.01 and 5, and, more preferably, between 0.1 and 3, of said salt (ch) including at least one chaotropic ion, [0077] between 0.005 and 5.0 preferably between 0.01 and 3.0, and, more preferably, between 0.1 and 2, of said water reducing polymer (b), and [0078] between 0.1 and 10 preferably between 0.5 and 5, and, more preferably, between 1 and 3 of said accelerator (c).

The Hydraulic Binder (a)

[0079] Advantageously, the hydraulic binder (a) is selected from the group consisting of ordinary Portland cement, calcium aluminate cement, calcium sulfoaluminate cement, belite cement, hydraulic lime, ground granulated blast furnace slag, basic oxygen furnace slag, ladle slag, super sulfated cement, cement kiln dust, or a mixtures thereof.

[0080] Ordinary Portland cements and normalized cements often include a small amount of gypsum or an alternative calcium sulfate, which acts as a set regulator. However, gypsum may be added to the hydraulic binder.

The Water Reducing Polymer (b)

[0081] In a preferred embodiment, the water reducing polymer (b) is selected from the group consisting of lignosulfonate polymers, melamine sulfonate polymers, naphthalene sulfonate polymers, polycarboxylic acid ether polymers, polyoxyethylene phosphonates, vinyl copolymers, and mixtures thereof.

The Accelerator in the Form of a Salt Containing at Least One Kosmotropic Anion (c)

[0082] The kosmotropic ion could be mono or multivalent.

[0083] In a preferred embodiment the kosmotropic ion of the accelerator (c) is an anion from the group consisting of carbonate (CO.sup.2—), sulfate (SO.sub.4.sup.2—), hydroxide (OH.sup.—), citrate (C.sub.6H.sub.5O.sub.7.sup.3*), phosphate (PO.sub.4.sup.3—), hydrogen phosphate (HPO.sub.4.sup.2—), dihydrogen phosphate (HPO.sub.4—), tartrate (C.sub.4H.sub.4O.sub.6.sup.2—), acetate (CH.sub.3COO.sup.—), formate (HCOO.sup.—), bicarbonate (HCO.sub.3—), orthosilicate (SiO.sub.4.sup.4—), metasilicate (SiO.sub.3.sup.2—), pyrosilicate (Si.sub.2O.sub.7.sup.6—), polyphosphates, polysilicates and thiosulfate (S.sub.2O.sub.2.sup.3—).

[0084] Advantageously, the cation of the accelerator (c) in the form of a salt is selected from the group consisting of sodium, potassium, and lithium.

The Salt Including at Least One Chaotropic Ion (ch)

[0085] The chaotropic ion of the salt (ch) could be an anion or a cation, either mono or multivalent.

[0086] In a preferred embodiment the chaotropic ion of the salt (ch) is advantageously selected from the group consisting of chloride (Cl.sup.—), bromide (Br.sup.—), nitrate (NO.sub.3—), chlorate (ClO.sub.3—), perchlorate (ClO.sub.4—), tetrafluoroborate (BF.sub.4—), iodide (I.sup.-), thiocyanate (SCN.sup.—), hexafluorophosphate (PF.sub.6—), guanidinium (C(NH.sub.2).sub.3+), trichloroacetate (CC.sub.l3COO.sup.—), dichloroacetate (CHCl.sub.2COO.sup.—), chloroacetate (CH.sub.2ClCOO.sup.—), tribromoacetate (CBr.sub.3COO.sup.—), or trifluoroacetate (CF.sub.3COO.sup.—).

[0087] Advantageously, said salt (ch) including at least one chaotropic ion is selected from the group consisting of potassium thiocyanate (KSCN), potassium nitrate (KNO.sub.3), potassium chloride (KCl), sodium thiocyanate (NaSCN), sodium nitrate (NaNO.sub.3), sodium chloride (NaCl), magnesium chloride (MgCl.sub.2), magnesium nitrate (Mg(NO.sub.3).sub.2), calcium chloride (CaCl.sub.2), calcium nitrate (Ca(NO.sub.3).sub.2) calcium thiocyanate (Ca.sub.2SCN), barium chloride (BaCl.sub.2), strontium nitrate (Sr(NO.sub.3).sub.2), guanidinium chloride (CH.sub.6ClN.sub.3) and guanidinium thiocyanate (C.sub.2H.sub.6N.sub.4S).

Salt (ch)/ Accelerator (c) Ratio

[0088] The efficiency of the chaotropic ion depends on several factors like the type of accelerator, the type of water reducing polymer, the ratios between water/binder composition/aggregates/gravels in the resulting wet concrete or industrial mortar composition. A person skilled in the art could determine the optimal activator (c)/salt (ch)/water reducing polymer ratio with routine experimentations.

[0089] However, in a preferred embodiment, in the method according to the invention, the dry weight ratio of salt (ch) including at least one chaotropic ion to said accelerator (c) is comprised between 0.01 and 3.0.

Water (d)

[0090] In a preferred embodiment, the weight ratio water to hydraulic binder (d/a) is comprised between 0.08 and 1.0, preferably between 0.25 and 0.9, and more preferably selected in the group comprising -advantageously consisting in- the following ranges: [0.25 ; 0.35[ ; [0.35 ; 0.45[ ; [0.45 ; 0.6[ ; [0.6 ; 0.9].

Supplementary Cementitious Material (e)

[0091] The supplementary cementitious material (e) is preferably selected from the group consisting of fly ash calcined and non-calcined clays, silica fume, basic oxygen furnace slag, natural pozzolanic materials, rice husk ash, activated recycled concrete fine aggregates or a mixtures thereof.

Filler Material (f)

[0092] The filler material (f) is preferably selected from the group consisting of ground limestone, ground dolomite, marble powder, siliceous sands, recycled concrete fine aggregates or a mixture thereof.

Additional Optional Components

[0093] The binder composition is advantageously enriched with one or several other components which are ingredients, notably functional additives preferably selected in the following list: [0094] Water retention agent.

[0095] A water retention agent has the ability to retain the mixing water before setting. The water is so trapped in the wet paste formulation which improves its bond. To some extent, the water is less absorbed by the support.

[0096] The water retention agent is preferably chosen from the group comprising: modified celluloses, modified guars, modified cellulose ethers and/or guar ether and their mixes, more preferably consisting of: methylcelluloses, methylhydroxypropylcelluloses, methylhydroxyethyl-celluloses and their mixes. [0097] Rheological agent

[0098] The possible rheological agent (also named a “thickener”) is preferably chosen from the group comprising, more preferably consisting in: clays, starch ethers, cellulose ethers and/or gums (e.g. welan guar xanthane, succinoglycans), modified polysaccharides -preferably among modified starch ethers-, polyvinylic alcohols, polyacrylamides, clays, sepiolites, bentonites, and their mixes, and more preferably chosen in the group of clays, bentonite, montmorillonite. [0099] Defoamer/Antifoams

[0100] The possible defoamer is preferably chosen in the group comprising, more preferably consisting in: polyether polyols and mixes thereof. [0101] Biocide

[0102] The possible biocide is preferably chosen in the group comprising, more preferably consisting in: mineral oxides like zinc oxide and mixes thereof. [0103] Pigment

[0104] The possible pigment is preferably chosen in the group comprising, more preferably consisting in: TiO.sub.2, iron oxide and mixes thereof. [0105] Flame retardant

[0106] The possible flame retardant (or flame proof agent), which makes it possible to increase the fire resistance and/or to shrink the speed of flame spreading of the composition is preferably chosen in the group comprising, more preferably consisting in: [0107] minerals preferably aluminium hydroxide [AI(OH).sub.3, ATH], magnesium hydroxide MDH, hydromagnesite, hydrates, red phosphorus, and boron compounds, preferably borates, [0108] organohalogen compounds, preferably organochlorines and more preferably such as chlorendic acid derivatives and chlorinated paraffins; organobromines such as decabromodiphenyl ether (decaBDE), decabromodiphenyl ethane, [0109] polymeric brominated compounds preferably brominated polystyrenes, brominated carbonate oligomers (BCO’s), brominated epoxy oligomers (BEO’s), tetrabromophthalic anyhydride, Tetrabromobisphenol A(TBBPA) and hexabromocyclododecane (HBCD), [0110] antimony preferably pentoxide and sodium antimonite, [0111] organophosphorus compounds preferably organophosphate, TPP, RDP, BPADP, tri-o-cresyl phosphate, [0112] phosphonates preferably DMMP and phosphinates, [0113] chlorophosphates like TMCP and TDCP. [0114] Air-entraining agents

[0115] Air-entraining agents (surfactants) are advantageously chosen in the group comprsing, more preferably consisting in, natural resins, sulfated or sulfonated compounds, synthetic detergents, organic fatty acids and their mixes, preferably in the group comprising, more preferably consisting in, the lignosulfonates, the basic soaps of fatty acids and their mixes, and, more preferably in the group comprising, more preferably consisting in the sulfonate olefins, the sodium lauryl sulfate and their mixes. [0116] Retarders

[0117] Retarders are advantageously chosen in the group, more preferably consisting in tartaric acid and its salts: sodium or potassium salts, citric acid and its salts: sodium (trisodium citrate) and their mixes; [0118] Fibres [0119] Dispersion powders [0120] Wetting agents [0121] Polymeric resins [0122] Complexing agents [0123] Drying shrinkage reducing agents based on polyols.

[0124] The total content of these optional other components is preferably comprised between 0.001% and 10% by weight of the total weight of the binder fraction.

Aggregate Fraction

[0125] Aggregates comprise a large category of particulate material used in construction, including sands, gravels, crushed stones, slag (not-granulated), recycled concrete and geosynthetic aggregates. They serve as reinforcement to add strength to the overall composite material.

[0126] The concrete or industrial mortar composition can also include fillers, for example based on quartz, limestone, or clays and mixtures thereof as well as light fillers, such as perlites, diatomaceous earth, expanded mica (vermiculite) and foamed sand, and mixtures thereof.

[0127] Advantageously, said concrete or industrial mortar composition also can include, apart from aggregates, one or several ingredients, especially functional admixtures, additions and fibres, which can be the same as the other optional component mentioned above in the “additional optional components” part.

[0128] The total content of these optional other components in the concrete or industrial mortar composition is preferably comprised between 0, 1 % and 10% by weight of the total weight of the aggregate fraction.

Process for Preparing Wet Concrete or Mortar Composition

[0129] The invention is also directed to a process for preparing wet concrete or mortar composition comprising a step of mixing together, simultaneously or not, separately or not, [0130] (a) at least one hydraulic binder, [0131] (b) at least one water reducing polymer, [0132] (c) at least one accelerator in the form of a salt containing at least one kosmotropic ion, [0133] (d) water, and [0134] (e) possibly one or more supplementary cementitious materials, and [0135] (f) possibly one or more filler materials, [0136] at least one salt (ch) including at least one chaotropic ion, and [0137] at least one aggregate fraction.

[0138] According to the present disclosure, the term “mixing” has to be understood as any form of mixing.

[0139] In a preferred embodiment a part of the binder and at least a part of the water are mixed together prior to the mixing with the aggregate.

[0140] In a preferred embodiment, the process is carried out with a weight ratio water to hydraulic binder (d/a) comprised between 0.08 and 1.0, preferably between 0.25 and 0.9, and more preferably selected in the group comprising -advantageously consisting in- the following ranges: [0.25 ; 0.35[ ; [0.35 ; 0.45[ ; [0.45 ; 0.6[ ; [0.6 ; 0.9].

[0141] In a preferred embodiment, for a given quantity of said at least one accelerator (c), quantities of said salt (ch) including at least one chaotropic ion and of said at least one water reducing polymer (b) are sufficient for both accelerating and managing the fluidity of the wet concrete or mortar composition, for a required duration after said mixing step, depending on the application, preferably for at least 2 hours after said mixing step.

Ready-Mix Concrete or Precast Concrete Composition

[0142] The invention also relates to a ready-mix concrete or precast concrete compositions, devoted in particular to building construction and civil engineering works, comprising at least one aggregate fraction, at least one salt (ch) including at least one chaotropic ion, and [0143] (a) at least one hydraulic binder, [0144] (b) at least one water reducing polymer, [0145] (c) at least one accelerator in the form of a salt containing at least one kosmotropic ion, [0146] (d) water, and [0147] (e) possibly one or more supplementary cementitious materials, and [0148] (f) possibly one or more filler materials.

[0149] The invention is particularly beneficial for ready-mix concrete or precast concrete. Indeed, the fluidity of these concretes has to be maintained over a time period covering the production at the plant, the delivery and the employment at the site of final use.

EXAMPLES

[0150] The yield stress is the stress threshold for permanent deformation of a composition and characterizes its intrinsic fluidity or workability.

Yield Stress Time Evolution Procedure

[0151] The nature and the content of each component is set forth in table 1 below. [0152] 1. The components of the hydraulic binder are weighed and added to a mixing cup. The total mass is 100 g. When present, chaotropic salt(s) and activator(s) are added to the dry hydraulic binder in excess of the 100 g. The resulting binder composition is mixed at 150 RPM using an overhead stirrer (IKA Eurostar 40) equipped with a propeller blade, for 30 seconds. [0153] 2. Tap water is weighed to the desired mass and added to a mixing cup. [0154] 3. The water reducing polymer is weighed to the desired mass using a syringe. [0155] 4. The tap water is added to the mixing cup containing the binder composition (i.e. hydraulic binder and salt(s) and/or activator(s)). The resulting mixture is stirred for 30 seconds at 150 RPM, then for 90 seconds at 550 RPM and then left to rest for 120 seconds. [0156] 5. After said 120 seconds, the weighed water reducing polymer is added, and the wet composition is stirred for an additional 60 seconds at 550 RPM. [0157] 6. Then, the wet composition is poured or scooped into the sample cup of an AR-2000-ex rheometer until the cup is full. The rheometer is equipped with vane concentric cylinders as its geometry. The geometry is lowered into the measuring position. [0158] 7. The rheometer stabilizes the binder at approximately 20° C. [0159] 8. The wet composition is mixed at a shear rate of 25/s for 30 seconds to remove bubbles and ensure homogeneity. [0160] 9. The rheometer geometry begins rotating at a shear rate of 0.1/s. The measurement of stress at this shear rate is taken as the yield stress. [0161] 10. The shear rate is increases from 0.1/s to 50/s taking measurements at 15 different shear rates with a logarithmic measurement interval. [0162] 11 .After completing the measurement at 50/s, the binder is mixed for 30s at 25/s as in Step 8. [0163] 12. Measurements are taken as in Step 10 but in reverse (starting at 50/s and slowing to 0.1/s). The measurement at 0.1/s is not taken as the yield stress due to hysteresis. [0164] 13. Steps 8-12 are repeated as many times as required to cover the desired test duration.

TABLE-US-00001 Sample Binder (weight %) Accelerator (weight % in respect with the binder) Chaotropic salt (weight % in respect with the binder) Water reducing polymer (weight % in respect with the binder) Weight ratio Chaotropic salt/Water reducing polymer Weight ratio Water/Hydraulic binder CE1 (counter-example) Ground limestone (40%) GGBS (30%) CEM 1 52.5 (20%) Ultrafine ground limestone (10% ) None None Sika ViscoCrete Tempo 653 (0.5%) 0 0.3 CE2 (counter-example) Ground limestone (40%) GGBS (30%) CEM 152.5 (20%) Ultrafine ground limestone (10%) Na.sub.2SO.sub.4 (1.5%) None Sika ViscoCrete Tempo 653 (0.5%) 0 0.3 CE3 (counter-example) Ground limestone (20%) GGBS (40%) CEM I 52.5 (40%) None None Sika ViscoCrete Tempo 10 (0.5%) 0 0.3 CE4 (counter-example) Ground limestone (20%) GGBS (40%) CEM I 52.5 (40%) Na.sub.2SO.sub.4 (0.75%) None Sika ViscoCrete Tempo 10 (0.5%) 0 0.3 CE5 (counter-example) CEM I 52.5 (50%) Metakaolin (30%) Ground limestone (15%) Gypsum (5%) None None Sika ViscoCrete Krono 26 (0.8%) 0 0.3 CE6 (counter-example) CEM I 52.5 (50%) Metakaolin (30%) Ground limestone (15%) Gypsum (5%) Na.sub.2SO.sub.4 (1.5%) None Sika ViscoCrete Krono 26 (0.8%) 0 0.3 E1 (Invention) Ground limestone (40%) GGBS (30%) CEM I 52.5 (20%) Ultrafine ground limestone (10%) Na.sub.2SO.sub.4 (1.5%) KSCN (2.0%) Sika ViscoCrete Tempo 653 (0.5%) 4 0.3 E2 (Invention) Ground limestone (40%) GGBS (30%) CEM I 52.5 (20%) Ultrafine ground limestone (10%) Na.sub.2SO.sub.4 (1.5%) Ca(NO.sub.3).sub.2 (3.0%) Sika ViscoCrete Tempo 653 (0.5%) 6 0.3 E3 (invention) Ground limestone (40%) GGBS (30%) CEM I 52.5 (20%) Ultrafine ground limestone (10%) Na.sub.2SO.sub.4 (1.5%) MgCl.sub.2 (1.0%) Sika ViscoCrete Tempo 653 (0.5%) 2 0.3 E4 (Invention) Ground limestone (40%) GGBS (30%) CEM I 52.5 (20%) Ultrafine ground limestone (10%) Na.sub.2SOa (1.5%) K(NO.sub.3).sub.2 (1.0%) Sika ViscoCrete Tempo 653 (0.5%) 2 0.3 E5 (Invention) Ground limestone (20%) GGBS (40%) CEM I 52.5 (40%) Na.sub.2SO.sub.4 (0.75%) Ca(SCN).sub.2. 4 H.sub.2O (0.75%) Sika ViscoCrete Tempo 10 (0.5%) 1.5 0.3 E6 (invention) Ground limestone (20%) GGBS (40%) CEM I 52.5 (40%) Na.sub.2SO.sub.4 (0.75%) Mg(NOa).sub.2. 4 H.sub.2O (0.75%) Sika ViscoCrete Tempo 10 (0.5%) 1.5 0.3 E7 (Invention) CEM I 52.5 (50%) Metakaolin (30%) Ground Limestone (15%) Gypsum (5%) Na.sub.2SO.sub.4 (1.5%) MgCl2 (1%) Sika ViscoCrete Krono 26 (0.8%) 2 0.3

[0165] FIG. 1 is a graph representing the yield stress versus time after mixing of the sample CE1, CE2 and E1.

[0166] FIG. 2 is a graph representing the yield stress versus time after mixing of the sample CE1, CE2 and E2.

[0167] FIG. 3 is a graph representing the yield stress versus time after mixing of the sample CE1, CE2 and E3.

[0168] FIG. 4 is a graph representing the yield stress versus time after mixing of the sample CE1, CE2 and E4.

[0169] FIG. 5 is a graph representing the yield stress versus time after mixing of the sample CE3, CE4 and E5.

[0170] FIG. 6 is a graph representing the yield stress versus time after mixing of the sample CE3, CE4 and E6.

[0171] FIG. 7 is a graph representing the yield stress versus time after mixing of the sample CE5, CE6 and E7.

[0172] As can be seen on these graphs in the absence of accelerator (c) and a salt (ch) including a chaotropic ion, the yield stresses of composition CE1 and CE5 are almost equal to 0 Pa and the yield stress of composition CE3 is around 1 Pa, these yield stresses do not significantly evolve with time. Such low yield stresses are due to the presence of a water reducing polymer which fluidifies the binder composition.

[0173] On the contrary, the addition of an accelerator (c) comprising a kosmotropic ion (CE2, CE4 and CE6) significantly increases the yield stress. The accelerator (c) significantly degrades the fluidity of the samples and the effect of the water reducing polymer is significantly reduced.

[0174] Thanks to the addition of a salt (ch) including a chaotropic ion (E1 to E7) according to the invention, it is possible to decrease the yield stresses.

Calorimetry

[0175] The total heat released by a sample can act as a proxy for hydration and/or strength development at early age.

[0176] The nature and the content of each component are set forth in table 1 above. [0177] 1. The components of the binder are weighed and added to a mixing cup. The total mass is 50 g. When present, salt(s) and activator(s) are added to the dry hydraulic binder in excess of the 50 g. The resulting binding composition is mixed at 150 RPM using an overhead stirrer (IKA Eurostar 40) equipped with a propeller blade for 30 seconds. [0178] 2. Tap water is weighed to the desired mass and added to a mixing cup. [0179] 3. The water reducing polymer is weighed to the desired mass using a syringe. [0180] 4. The tap water is added to the mixing cup containing the binding composition (i.e. hydraulic binder and salt(s) and/or activator(s)). The resulting mixture is stirred for 30 seconds at 150 RPM and, then for 90 seconds at 550 RPM and then left to rest for 120 seconds. [0181] 5. After said 120 seconds, the weighed water reducing polymer is added, and the wet composition is stirred for an additional 60 seconds at 550 RPM. [0182] 6. Approximately 5 g of the wet composition is placed inside a plastic ampoule. The mass is recorded, and the ampoule is sealed. [0183] 7. The ampoule is placed inside a measurement cell in a TAM Air isothermal micro-calori meter. [0184] 8. The calorimeter measures the heat flow coming from the wet composition sample over a given measurement duration.

[0185] FIG. 8 is a graph representing the heat generated per unit mass over the first 24 hours after mixing of the sample CE1 and E1.

[0186] FIG. 9 is a graph representing the heat generated per unit mass over the first 24 hours after mixing of the sample CE1 and E2.

[0187] FIG. 10 is a graph representing the heat generated per unit mass over the first 24 hours after mixing of the sample CE5 and E7.

[0188] As can be seen on these graphs, the heat produced by samples E1 and E2 are greater than sample CE1 for the duration of the testing period and the heat produced by sample E7 is greater than sample CE5 for the duration of the testing period. The amount of heat produced by a paste sample can act as a proxy for strength development as the hydration of cementitious systems is an exothermic process. Thus, it would be expected that mortar and concrete compositions would achieve higher early age strengths thanks to the invention.